A French curve is a tool used to draw different curves there are lots of swirls and circles so if a circle guide isn't good enough the French curve can draw and curves possible.
ruler
A ruler.
French curves are used as templates to draw curved lines. They are used in both designing clothing and designing cars. The person drawing the dress or car places the appropriate size curve on the paper and pencils around it.
Compass
A drawing compass - often referred to as a pair of compasses.
Rheostat is the name of an instrument used to vary electrical resistance.
a transit, a theodolite or a builders level. they are used for laying out curves, building layout lines and wall heights/plumb
There are many saws used for cutting wood. I will list as many as I can. There are Handheld
To draw circles you need to use a compass
syringe
Timepieces.